Unlike a Bunsen burner, a Tirrill burner allows adjustment of both the air supply and the gas supply. Adjustable air ports regulate the air supply and a brass needle valve regulates the gas supply. Accepts burner tubing 3/8" inside diameter (Catalog No. AP8286). Maximum temperature of flame can reach 1560 ºC. *AP1019, natural gas model, and AP1020, bottled gas model, are furnished with flame retainers. AP1018, artificial gas model, is not furnished with a flame retainer.